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Phillipsite-Na crystal
Photo by Violet Anderson
László Horváth specimen
© Royal Ontario Museum
Phillipsite-Na crystals
© Doug Merson
(Na,K,Ca)1-2(Si,Al))O16 · 6H
Phillipsite is widespread in small quantities at Mont Saint-Hilaire and
is indistinguishable visually from harmotome.
PHYSICAL CHARACTERISTICS:
Color is usually colorless or white.
Luster is vitreous.
Diaphaneity is transparent to translucent.
Crystal System is monoclinic;
Crystal Habits include very small clusters of cruciform twins and
prismatic crystals.
Cleavage {010} and {100} are distinct.
Fracture is uneven to subconchoidal.
Hardness is 4 – 4.5
Specific Gravity is approximately 2.2 g/cm
Streak is white.
Associated Minerals include aegirine, albite, amphibole group,
analcime, ancylite, calcite group, catapleiite, cordylite, elpidite,
eudialyte, fluorapatite, galena, microcline, monteregianite,
natrolite, pyrophanite and titanite.
Distinguishing Features: Crystal habit and twinning habit.
Origin: Named in 1825 after William Phillips (1775-1828), British
mineralogist and geologist.
CLASSIFICATION:
Dana System
# 77.1.3a.1
Strunz Classification
# VIII/J.25-50
REFERENCES:
MinRec 21:330 (1990), Dana 8:1665-1666 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
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Phillipsite-Na crystals
Photo by Violet Anderson
© Royal Ontario Museum